Torch tip and method of fabricating the same

ABSTRACT

A torch tip of the type adapted to burn a mixture of fuel gas and oxygen, and method of forming the same. The tip is formed of two parts, one of which is an outer tubular housing and the other of which is force-fitted into the tubular housing. The part which is force-fitted into the tubular housing comprises an elongated shank portion having a central bore extending therethrough to convey pure oxygen to a flame at one end of the tip. At opposite ends of the shank portion are enlarged diameter portions, both of which are force-fitted into the opposite ends of the outer tubular housing. Axial bores are drilled in the enlarged diameter portions and radially spaced around the axis of the central bore to convey a mixture of oxygen and fuel gas to the flame area at one end of the tip. Intermediate the enlarged diameter end portions on the shank portion are enlarged portions which substantially abut the inner peripheral surface of the outer tubular housing to prevent collapse of the same under impact loads. These intermediate portions are provided with milled slots which permit gas to pass from one end of the tip to the other through successive plenum chambers which facilitate good mixing of an oxygen-fuel gas mixture.

United States Patent 11 1 Yerkins [4 1 Sept. 17, 1974 TORCH TIP AND METHOD OF FABRICATING THE SAME [75] Inventor: Stephen J. Yerkins, Glenshaw, Pa.

[73] Assignee: Goss Gas, Inc., Glenshaw, Pa.

[22] Filed: May 14, 1973 [21] Appl. No.: 360,305

[52] US. Cl. 239/424.5, 239/600, 29/157 C,

[51] Int. Cl F23d 15/04 [58] Field of Search 29/157 C, 525', 239/4164, 239/4245, 600

[56] References Cited UNITED STATES PATENTS 2,363,250 ll/1944 Jenkins 239/4245 X 2,433,539 12/1947 Westerman.... 29/157 C X 2,468,824 5/1949 Hughey 29 157 c x 2,993,531 7/1961 Spies et al 239/4245 3,006,026 10/1961 Martin et a1... 29/525 X 3,477,112 11/1969 Yerkins 29/157 C 3,540,656 ll/l970 Yerkins 239/4245 Primary Examiner-Richard .1. Herbst Assistant Examiner-D. C. Rei'ley, Ill Attorney, Agent, or FirmBrown, Murray, Flick &

Peckham [57] ABSTRACT A torch tip of the type adapted to burn a mixture of fuel gas and oxygen, and method of forming the same. The tip is formed of two parts, one of which is an outer tubular housing and the other of which is forcefitted into the tubular housing. The part which is force-fitted into the tubular housing comprises an elongated shank portion having a central bore extending therethrough to convey pure oxygen to a flame at one end of the tip. At opposite ends of the shank portion are enlarged diameter portions, both of which are force-fitted into the opposite ends of the outer tubular housing. Axial bores are drilled in the enlarged diameter portions and radially spaced around the axis of the central bore to convey a mixture of oxygen and fuel gas to the flame area at one end of the tip. Intermediate the enlarged diameter end portions on the shank portion are enlarged portions which substantially abut the inner peripheral surface of the outer tubular housing to prevent collapse of the same under impact loads. These intermediate portions are provided with milled slots which permit gas to pass from one end of the tip to the other through successive plenum chambers which facilitate good mixing of an oxygen-fuel gas mixture.

5 Claims, 3 Drawing Figires TORCH TIP AND METHOD OF FABRICATING THE SAME BACKGROUND OF THE INVENTION As is known, torch tips are constructed to provide one or more heating jets and an auxiliary jet. The heating jets burn oxygen and L-P gases, oxygen and hydrogen or oxygen and another gas which will burn in the presence of oxygen and which will provide sufficient heat to melt a particular metal. The auxiliary jet is usually a jet of pure oxygen.

Torch tips of the type described above are usually formed from a single piece of copper or copper alloy. They have a relatively large central bore which provides the auxiliary jet and-a plurality of relatively small bores which are arranged in a circle about the central bore and provide the aforementioned heating jets. Inasmuch as the central bore has a relatively large diameter, it is easily drilled without any major problems. The smaller bores, on the other hand, have small diameters and extend substantially the entire length of the torch tip. As a result, certain problems are encountered in drilling the small diameter bores; and the process is tedious and time consuming. The small diameter bores are normally drilled in two steps. That is, each small bore is started by drilling, for example, through the back end of the torch tip approximately halfway therethrough. They are then completed by drilling through the front end of the torch tip. The problem of drilling small diameter bores of this type is particularly severe in tips of relatively long length on the order of about four inches, such as those used for steel scarfing applications.

In US. Pat. No. 3,540,656, a relatively short torch tip is shown formed of two parts which eliminate the necessity for drilling small diameter holes through the entire length of the tip. It comprises a tubular housing having a back wall adapted for connection to a source of combustion gases, and an insert which is inserted through the open front end of the housing. The insert includes a hub disposed within the front end of the housing and a stem extending through the housing and into an axial bore formed in the back wall. In this manner, a sealed, annular gas passageway is formed between the stem and the tubular housing which communicates at its forward end with drilled openings in the forward hub and with passageways in the back wall.

The tip shown in US. Pat. No. 3,540,656, while satisfactory for relatively small tips, is intended only for applications where the strength of the tip is of secondary importance. That is, the annular gas passageway formed between the shank of the insert and the tubular housing makes it possible to collapse the outer housing, particularly in the case of large torch tips such as those used in scarfing applications and the like.

SUMMARY OF THE INVENTION In accordance with the present invention, a torch tip is provided which eliminates the necessity for drilling excessively long bores through the entire length of the tip while at the same time preserving the structural integrity of the tip.

In accordance with the invention, a torch tip is formed from two pieces comprising an outer tubular housing open at both ends and having an interior axial bore provided with a reduced diameter portion at the forward tip end thereof. The second element of the tip comprises an elongated shank portion having integral, enlarged diameter portions at its opposite ends. One of the enlarged diameter end portions is force-fitted into the reduced diameter portion at the forward tip end of the tubular housing; while the other enlarged diameter portion is force-fitted into the opposite end. A central axis bore extends through the second element for conveying oxygen to the forward tip end of the tubular housing; while axially-extending bores are circumferentially spaced around the enlarged diameter portions at the opposite ends of the shank portion for conveying a mixture of fuel gas and oxygen to the tip end in a space defined between the outer tubular housing and the shank portion.

In order to prevent collapse of the outer wall of the tubular housing, a plurality of enlarged diameter portions are provided on the shank portion intermediate the enlarged portions at the ends of the second element, the outer peripheries of the intermediate portions being in substantial contact with the inner peripheral surface of the outer tubular housing. Axiallyextending slots are provided in the intermediate portions for permitting gas to flow from the circumferentially-spaced bores in the enlarged diameter portion at one end of the second element to those in the enlarged diameter portion at the tip end of the tubular housing.

In forming the tip, the outer tubular housing and the second element are machined to provide the structures described above. Thereafter, the second element is inserted into the tubular housing and thereafter forced under pressure until a force-fit is effected at both ends between the tubular housing and the second element.

The above and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings which form a part of this specification, and in which:

FIG. 1 is an exploded cross-sectional view of the torch tip of the invention showing the two elements from which it is formed;

FIG. 2 is a cross-sectional view taken substantially along line IIII of FIG. 1; and

FIG. 3 is a cross-sectional view of the completed torch tip assembly of the invention showing its connection to a source of oxygen and an oxygen-fuel gas mixture.

With reference now to the drawings, the torch tip shown includes an outer tubular housing 10 having a flange 12 at the trailing end thereof. The inner periphery of the tubular housing 10 is divided into four portions. An intermediate portion 14 is formed by drilling, leaving a relatively rough inner peripheral surface. The forward portion 16 is reamed and is of smaller diameter than the portion 14. The surface of the inner periphery of portion 16 is smooth so as to receive the forward end of the second element of the torch tip in a manner hereinafter described. At the trailing end of the portion 14 is a third portion 18 also provided with a smooth inner peripheral surface. Portion l8 communicates with a recess 20 as shown.

Inserted into the tubular housing 10 is a second element 22 comprising a shank portion 24 having enlarged diameter portions 26 and 28 at its opposite ends. Axially drilled through portion 26 is a plurality of passageways or bores 30. Similarly, bores 32 are formed in the portion 28; however the bores 32 and 30 are relatively short. Intermediate the two enlarged diameter portions 26 and 28 and integral with the shank portion 24 are intermediate enlarged diameter portions 34 and 36 each provided with a plurality of axially-extending slots 38 as is perhaps best shown in FIG. 2. Extending centrally through the second element 22 along its axis is a central bore 40. Projecting outwardly from the enlarged diameter portion 28 is a stub portion 42 which forms the male element of a coupling adapted to convey oxygen to the central bore 40 and a mixture of oxygen and fuel gas to the passageways 32 as will hereinafter be described with reference to FIG. 3.

In forming the torch tip of the invention, the outer tubular housing and the second element 22 are initially machined, the inner peripheral portions 16 and 18 being reamed to provide smooth surfaces thereon. The diameters of the portion 26, as well as the portions 34 and 36, are slightly smaller than the diameter of portion 14 of the tubular housing 10. Consequently, when the element 22 is inserted into the trailing end of the tubular housing 10, the enlarged diameter portions 26, 34 and 36 can easily slide along the inner peripheral surface 14. The diameter of portion 26, however, is larger than that of the inner peripheral smooth surface 16 at the forward end of the tip. As a result, the portion 26 will not easily slide into the portion 16 but must be force-fitted by applying pressure to the element 22. The same is true of surface 44 on portion 28. It must be force-fitted into the portion 18 of the tubular housing 10 until a flange 46 on the enlarged diameter portion 28 abuts the bottom of the recess 20.

The completed torch tip is shown in FIG. 3 connected to sources of fuel gas. One source of fuel gas is identified by the reference numeral 48 and comprises pure oxygen. This is conveyed to the central bore 40 in the insert or element 22. The other source 50 com- "adapter head 56. These communicate with the passageways 32 in the enlarged diameter portion 28. The tip itself is secured to the adapter head 56 by means of an internally threaded cap 58 which engages the flange 12 at the trailing end of the torch tip and is threaded onto cooperating threads on the outer periphery of the adapter head 56. Pure oxygen is thus conveyed to the left or forward end of the tip through the passageway or bore 40; while a mixture of oxygen and L-P gases or other fuel gas is conveyed through passageways 52, thence through bores 32 and into the space defined between the outer tubular housing 10 and the outer periphery of the shank portion 24. The space between the tubular housing 10 and the shank portion 24 provides a series of plenum chambers 60 wherein exceptionally good mixing of the oxygen and L-P gases is achieved before passing through bores 30 in the enlarged diameter portion 26 at the forward end of the tip. The enlarged diameter portions 34 and 36 intermediate the end portions 26 and 28 substantially abut the inner periphery of the tubular housing 10 in the portion 14 thereof and thus prevent a possible collapse of the wall of the tubular housing under impact loads. At the same time, the slots 38 in the portions 34 and 36 permit the gas to pass from one plenum chamber to the next in traveling from bores 32 to bores 30.

The present invention thus provides an improved heavy-duty torch tip having exceptionally good strength characteristics while at the same time being cheap to manufacture since the bores surrounding the central bore need not be drilled along the entire length of the tip.

Although the invention has been shown in connection with a certain specific embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

What is claimed is:

l. The method of forming a torch tip from two elements which comprises providing a first element consisting of a tubular housing open at both ends, forming a first smooth inner peripheral surface at the forward tip end of said housing which is of smaller diameter than the remainder of the inner peripheral surface of said housing, forming a second smooth inner peripheral surface at the other end of said housing which is of larger diameter than the remainder of the inner peripheral surface of said housing, forming a second element having a shank portion and integral enlarged diameter portions at its opposite ends, one of said enlarged diameter portions being of slightly larger diameter than said first smooth peripheral surface and the other of said enlarged diameter portions being of slightly larger diameter than said second smooth peripheral surface, forming intermediate said enlarged diameter end portions at least one enlarged diameter portion which is slightly smaller in diameter than said remainder of the inner periphery of said housing, drilling a bore along the axis of said second element, drilling a ring of axially-extending bores in the enlarged diameter portions at opposite ends of the shank. portion with said axially-extending bores adapted to communicate with a space defined between said outer tubular portion and said shank portion, forming axially-extending slots in said intermediate enlarged portion to permit gases to pass therethrough, inserting said one enlarged portion of the second element into the end of said tubular housing opposite its tip end until said one enlarged portion engages said first smooth inner peripheral surface, and thereafter forcing said second element further into the tubular housing to effect a forced fit between said elements at the areas of the enlarged diameter portions at opposite ends of the shank portion.

2. The method of claim 1 wherein a plurality of enlarged diameter portions is formed intermediate said enlarged diameter end portions, and including the step of forming axially-extending slots in all of said intermediate enlarged portions to permit gases to pass therethrough.

3. A twopiece torch tip comprising an outer tubular housing open at both ends and having an interior axial bore provided with a reduced diameter portion at the forward tip end thereof, a second member comprising an elongated shank portion having integral enlarged diameter portions at its opposite ends, one of said enlarged diameter end portions being force-fitted into said reduced diameter portion at the forward tip end of said outer tubular housing, a central axial bore extending through said second member for conveying oxygen to the forward tip end of said tubular housing, axiallyextending bores circumferentially-spaced around said enlarged diameter portions at the opposite ends of said portion to those in the enlarged diameter portion at the tip end of the tubular housing.

4. The torch tip of claim 3 wherein the means in said intermediate portion for permitting gas flow comprises milled axially-extending slots in the periphery of said intermediate portion.

5. The torch tip of claim 4 wherein a plurality of enlarged diameter portions intermediate the end portions is spaced along the shank portion. 

1. The method of forming a torch tip from two elements which comprises providing a first element consisting of a tubular housing open at both ends, forming a first smooth inner peripheral surface at the forward tip end of said housing which is of smaller diameter than the remainder of the inner peripheral surface of said housing, forming a second smooth inner peripheral surface at the other end of said housing which is of larger diameter than the remainder of the inner peripheral surface of said housing, forming a second element having a shank portion and integral enlarged diameter portions at its opposite ends, one of said enlarged diameter portions being of slightly larger diameter than said first smooth peripheral surface and the other of said enlarged diameter portions being of slightly larger diameter than said second smooth peripheral surface, forming intermediate said enlarged diameter end portions at least one enlarged diameter portion which is slightly smaller in diameter than said remainder of the inner periphery of said housing, drilling a bore along the axis of said second element, drilling a ring of axially-extending bores in the enlarged diameter portions at opposite ends of the shank portion with said axially-extending bores adapted to communicate with a space defined between said outer tubular portion and said shank portion, forming axially-extending slots in said intermediate enlarged portion to permit gases to pass therethrough, inserting said one enlarged portion of the second element into the end of said tubular housing opposite its tip end until said one enlarged portion engages said first smooth inner peripheral surface, and thereafter forcing said second element further into the tubular housing to effect a forced fit between said elements at the areas of the enlarged diameter portions at opposite ends of the shank portion.
 2. The method of claim 1 wherein a plurality of enlarged diameter portions is formed intermediate said enlarged diameter end portions, and including the step of forming axially-extending slots in all of said intermediate enlarged portions to permit gases to pass therethrough.
 3. A two-piece torch tip comprising an outer tubular housing open at both ends and having an interior axial bore provided with a reduced diameter portion at the forward tip end thereof, a second member comprising an elongated shank portion having integral enlarged diameter portions at its opposite ends, one of said enlarged diameter end portions being force-fitted into said reduced diameter portion at the forward tip end of said outer tubular housing, a central axial bore extending through said second member for conveying oxygen to the forward tip end of said tubular housing, axially-extending bores circumferentially-spaced around said enlarged diameter portions at the opposite ends of said shank portion for conveying a mixture of fuel gas and oxygen to said tip end in a space defined between said outer tubular housing and said shank portion, at least one enlarged diameter portion on the shank portion intermediate said enlarged diameter portion at the ends of the shank portion, the outer periphery of the intermediate portion being in substantial contact with the inner peripheral surface of the outer tubular housing, and means in said intermediate portion for permitting gas to flow from the circumferentially-spaced bores in the enlarged diameter pOrtion at one end of the shank portion to those in the enlarged diameter portion at the tip end of the tubular housing.
 4. The torch tip of claim 3 wherein the means in said intermediate portion for permitting gas flow comprises milled axially-extending slots in the periphery of said intermediate portion.
 5. The torch tip of claim 4 wherein a plurality of enlarged diameter portions intermediate the end portions is spaced along the shank portion. 